It has been known to obtain an article having matte surface by electrocoating with electrodepositable paint containing internally crosslinked micro resin particles (hereinafter referred to as "micro gel particles") prepared by polymerizing an ethylenically unsaturated monomer (see Japanese patent publication (unexamined) Nos. 93762/1983 and 49766/1981). The micro gel particles are advantageous not only in providing matte surface, but also in coating properties and throw power.
The micro gel particles, however, should be mixed with a resin which is water-soluble or water-dispersible and which has charges necessary for electrodeposition if it is applied for electrocoating, because they do not have suitable charges and are insoluble in an aqueous medium. On the other hand, the micro gel particles deteriorate storage stability and workability of electrocoating and it therefore is difficult to formulate in a large amount into a paint.
Japanese patent publication (unexamined) No. 31199/1986 discloses a water dispersion prepared by neutralizing a heat reaction product of an alpha,beta-ethylenically unsaturated polycarboxylic acid resin and an alcoxylated methylol melamine. The dispersion is used for providing a matte surface by electrocoating. The dispersion is not cationic but anionic.